Blending neutral dyeing 1:2 premetallized azo dyed acid modified acrylic fiber with the same fiber undyed and disperse or cationic dyeing the blend

ABSTRACT

An acrylic fiber containing acid groups but no basic groups is dyed with a neutral dyeing 1:2 type premetallized acid dye in a bath containing at least one water-soluble inorganic monovalent metal salt, divalent metal salt or ammonium salt. The resultant dyed material is deeply colored and of excellent fastness, is characterized by minimum dye migration, and is therefore useful in the manufacture of multi-colored dyed acrylic fiber materials.

United States Patent [191 Shibukawa et al.

[5 BLENDING NEUTRAL DYEING 1:2

PREMETALLIZED AZO DYED ACID MODIFIED ACRYLIC FIBER WITH THE SAME FIBERUNDYED AND DISPERSE OR CATIONIC DYEING THE BLEND [75] Inventors: TakashiShibukawa; Masanobu Hoten, both of Saidaiji; Naoki Hayasaki, Hirakata;Shigeo Mizutani, Mishinomiya, all of Japan [73] Assignee: Japan ExlanCompany Limited, Osaka, Japan [22] Filed: June 5, 1972 [21] Appl. No.:259,840

Related US. Application Data [63] Continuation-impart of Ser. No.654,054, July 18,

1967, abandoned.

52 US. Cl 8/21 A, 8/168, 8/42 A,

- 8/26, 8/15 51 Int. Cl D06p 3/82 [58] Field of Search 8/15, 21 A, 168,65, 42 A [56] References Cited UNITED STATES PATENTS 2,636,802 4/1953Wesp will ..8/177R 1111 3,841,830 14 1 Oct. 15,1974

3,273,956 9/1966 Fujita 8/65 A 7 OTHER PUBLICATIONS Cheetham, DyeingFibre Blends, pgs. 192-199, 202-207 Pub. by Van Nostrand Co. London,Eng.

Ricard Tessuer, Amer. Dyestuff Rep. 12/18/67 page 1,0161,019.

Primary ExaminerDonald Levy Attorney, Agent, or Firm-Wenderoth, Lind &Ponack [5 7] ABSTRACT dyed acrylic fiber materials.

2 Claims, N0 Drawings BLENDING NEUTRAL DYEING 1:2 PREMETALLIZED AZO DYEDACID MODIFIED ACRYLIC FIBER WITH THE SAME FIBER UNDYED AND DISPERSE ORCATIONIC DYEING THE BLEND This application is a continuation-in-part ofSer. No. 654,054, filed July 18, 1967, now abandoned.

This invention relates to a method for multi-colored dyeing of acrylictextile materials. More particularly, it relates to a method formulti-colored dyeing of textile material composed of fibers of acrylicpolymer containing acid groups (hereinafter sometimes referred to asacrylic synthetic fiber containing no basic groups). In accordance withthis method, a first dark-shade dyeing of a part of the fiber materialis carried out with a neutral dyeing 1:2 type pre-metallized acid dyewhich possesses excellent potting fastness, and after the fiber materialthus dyed is mix-spun or otherwise blended with the counterpart fibermaterial, cross dyeing of the resulting textile'material is carried outwith another dye of a different color.

With regard to cross dyeing, where a textile material composed of thesame or two similar fibers having identical functional groups is dyed toa variegated color pattern, it has been-conventional practice to carryout the first dyeing of that part of the textile material to be dyed ina dark shade, and then to carry out a second dyeing (cross dyeing) ofthe entire assembly with a dye whose color contrasts with that of thedye used in the first dyeing.

However, when a textile material composed of an acrylic fiber containingacidic groups but no basic groups which has been dyed to a dark shadewith a dye exhibiting cationic behavior in the dyeing bath (hereinafterreferred to as cationic dye) is mixed with an undyed textile materialand the entire assembly is subjected to a second dyeing with anothercationic dye of a different color to obtain a multi-colored ,dy'earticle, the dye adsorbed on that part of the material which has beendyed in the first dyeing tends to bleed out during the second dyeing.The result is that the fiber to be dyed in the second dyeing is stained,and accordingly, the objective two color effect can not be obtained.

The acrylic textile materials which are subjected to dyeing inaccordance with the present invention are composed of acrylic polymerscontaining acid groups but no basic groups. In the process of producingthe acrylic polymer or copolymer, strong acidic groups such as sulfateor sulfonate groups are introduced into the terminals of the moleculethrough the utilization of persulfuric acid, sulfurous acid, bisulfuricacid or their salts as a polymerization initiator. Alternatively, theacidic groups are introduced through copolymerization with unsaturatedmonomers containing sulfonate groups, such as styrenesulfonic acid,vinyl sulfonicv acid, allylsulfonic acid, methallylsulfonic acid, aswell as their salts, or with unsaturated monomers containing carboxylicacid groups, such as acrylic acid, methacrylic acid and itaconic acid aswell as their salts. By these methods the resultant acrylic fibercontains acid groups but no basic groups, and is thus rendered receptiveto cationic dyes. Particularly preferred are those acrylic fiberscontaining sulfonate groups.

Cationic dyes are widely used as well as disperse dyes to dyehydrophobic synthetic fibers. The dyeing of an acrylic synthetic fiberwith a cationic dye is apparently based on the reversible ion-exchangereaction schematically illustrated below.

(fiber SOfNa (dye) Cl 2 (fiber ls um) Mm" It is apparent that if a largeamount of the cationic substance to be adsorbed selectively on theacidic groups of the fiber is freshly added to the dyeing system, thereaction proceeds from right to left and, consequently, the dye whichhas already attached itself to the fiber is liberated as it undergoes anexchange with the freshly added cationic substance.

This phenomenon becomes a practical problem when there are introducedchanges such as in pH, due to the addition of acid or alkali, or whenother materials are added to the dye bath, such as the addition ofinorganic salts, the cationic dye of a different color to be used in thecross or second dyeing bath, and the cationic retarder to be used insaid second bath. The result is that the dark-shade dye used in thefirst bath bleeds out into the second bath, so that the fiber to be dyedin the second bath can not be dyed satisfactorily. This phenomonon isobserved even when using the cationic dyes described in the JapaneseIndustrial Standards (JlS) as being satisfactory'in potting fastness.Thus, such a dyeing process can not be successfully adopted forpractical purposes.

' As regards disperse dyes, it is known from the Journal of the Societyof Fiber Science and Technology, J apan, Vol. 21, (March, 1965) pp. 156to 163 and the synopsis of the proceedings of the Spring Convention ofthe Society of Fiber Science and and Technology, Japan- (1964), pp. 28that the dyeing mechanism is based on Henrys distribution law. From thisfact, as well as from the fact that the diffusion of dye into a fiber isconsiderably increased above C., the disperse dye which has once beenadsorbed on the textile substrate is redistributed into the undyedsubstrate fiber through the second dyeing bath.

The conclusion that may be drawn from the above observations is thatsuch dyeing processes can not be practically applied.

It has now been discovered that when an acrylic synthetic fibercontaining acid groups but containing no basic groups'is dyed withneutral dyeing l:2 type premetallized acid dyes in a bath containing atleast one water-soluble inorganic salt selected from the groupconsisting of monovalent metal salts, divalent metal salts andammonium-salts, a dyed material which is deeply colored and possessesexcellent fastness, with a minimum of dye migration in particular, isobtained. The present invention is based on this novel finding.

The principal object of the invention is to obtain an unstainedmulti-colored dyed material of an acrylic synthetic fiber containingstrong acidic dissociable groups but no basic dissociable groups.Another object is to attain a multi-colored acrylic textile productwhich has excellent fastness. Other objects will become apparent fromthe following description of the invention.

The objects of the invention can be accomplished by carrying out afirstdyeing of an acrylic textile material in a dark shade with a neutraldyeing 1:2 type premetallized acid dye in the presence of at least onewater-soluble inorganic salt selected from the group consisting ofmonovalent metal salts, divalent metal salts and ammonium salts.

3 The textile material is selected from fibers, spun yarns and othertextile products, whether woven or knitted, composed only of acrylicsynthetic fibers con taining acid groups but no basic groups.

Then, a second dyeing of the other textile material is carried out witha cationic or disperse dye of a different color after thefirst-mentioned dyed material is combined with the second mentionedundyed material by means of blending, mixspinning, mix-plying,blendweaving or knitting. Thus, the second-mentioned material would notbe dyed in the first dyeing, but only in the second dyeing.

As to the dyeing of the acrylic synthetic fiber containing acid groupsbut no basic groups, with a neutral dyeing 1:2 ltype pre-metallized aciddye, kinetic and equilibrium studies of such dyeing behavior have beencarefully investigated. It has been discovered that while 7 thediffusion of both cationic and disperse dyes increases greatly as thedye bath temperature reaches 70 C to 90 C, the diffusion of the neutraldyeing 1:2 type pre-metallized acid dyes at these temperatures is lowdue to their large molecular volume, and that as the dye bathtemperature is increased to more than 100 C to 110 C, the microbrownianmotion of the fiber molecules is so invigorated that the diffusion ofthe premetallized dyes into the fiber is conspicuously increased,resulting in an adsorption isotherm which is substantially shown asHenrys distribution law. Furthermore, when the inorganic salt used inthe present invention is added to the dye bath, the salt considerablyincreases the distribution of the 1:2 type pre-metallized acid dye intothe fiber, thereby making it possible to obtain a dark shade, which hasbeen considered particularly difficult to attain.

Generally speaking, dyeing to a dark shade an acrylic synthetic fibercontaining acid groups but no basic groups with a neutral dyeing 1:2type pre-metallized acid dye may be attained by dyeing the material in adye bath containing at least 0.5 percent by weight of a divalent metalsalt or at least.1.0 percent by weight of a monovalent metal or ammoniumsalt, based on the weight of the dye bath, at a dyeing temperature of100 C or higher. Stateddifferently, it requires the use of temperaturesof at least 100 C., preferably 100-l 30 C., to effect a good diffusionof the dyestuff, which possesses a large molecular volume, into thefiber, and any dye bath temperature below 100 C. would result in aconsiderable reduction in the dyeability of the fiber. A temperatureabove 130 C is not preferable because the acrylic fiber will bedeteriorated at such a high temperature.

The addition of an inorganic salt to the dyeing bath is essential whenanincreased partition of the dye to the fiber is to be attained. Thus, thepresence of 1.0 percent by weight or more of the monovalent metal'orammonium salts or 0.5 percent by weight or more of a divalent'metal saltin the dye bath is essential, .and no practically satisfactory dyeingcan be expected when the concentration of the inorganic salt is lowerthan this amount. it is preferable that the amount of the inorganicsalt(s) does not exceed 5 percent by weight because the presence of anexcessive amount may cause undesirable aggregation of the dye. i

. The water-soluble inorganic monovalent metal and ammonium salts thatcan be effectively employed according to this invention include thehalides, sulfates and phosphates orv alkali metals (sodium, potassium,

etc.) and ammonia, those salts which are neutral in aqueous solutionsbeing particularly preferred. Specific examples of such salts are sodiumsulfate, sodium chloride, ammonium chloride, ammonium sulfate andpotassium sulfate. The salts may be effectively employed either singlyor in combination with one or more oth ers.

Examples of water-soluble inorganic divalent metal salts are calciumchloride, barium chloride, zinc chloride, magnesium chloride, cadmiumchloride, zinc sulfate, magnesium sulfate, zinc nitrate, cadmiumnitrate, calcium thiocyanate and mixtures of any two or more of them. Afurther advantage of the use of such divalent metal salt is that thedivalent metal ion, e.g. Ca, Ba and Zn, will combine with the acidgroups in the fiber to block the sites for the cationic dye so that inthe subsequent dyeing with a cationic dye the staining of the first-dyedfiber with the second dye (cationic dye) is prevented'Therefore the useof the divalent salts is preferred. 7

As will be seen from the previously mentioned fact that the dyeingbehavior of the neutral dyeing 1:2 type premetallized acid dye relativeto the acrylic synthetic fiber substantially follows Henrys distributionlaw, it is necessary, when the fiber is to be dyed to a dark shade, thatthe dye concentration of the bath is high. For this purpose, the initialconcentration of the dye in the bath should be 0.2 percent by weight ormore. For economical reasons, the upper limit of the dye concentrationwould be about 1 percent.

The neutral dyeing 1:2 type pre-metallized acid dyes used in thisinvention are those in which two dyecomponent molecules are coordinatedon a single metal atom, as represented by the formula wherein Me ischromium or cobalt R, R", R' and R" are,independently of each other,substituents ordinarily possessed by dyestuffs, such as sulfonyl,sulphamyl, lower( 1-6) acylamino, lower (1-6) alkyl, phenyl, nitro andhydroxyl groups, and X is a monovalent metal atom, such as sodium. Thestructure of the dye so formed is anionic, with the counterpart ionbeing exemplified by the sodium ion. All these dyes are watersolublechromiumor cobalt-containing azo dyes containing no ionizing lyophilicgroups and no ionizing polar groups, in which two dye molecules arecombined with one metal atom. Thus, the dyes do not contain sulfonicacid groups. Any such neutral dyeing 1:2 premetallized acid dye can beused in the present invention, such as those fully described in TheJournal of the Society of Dyers and Colourists, Vol. 71 (1955) pages705-724. These neutral dyeing 1:2 type premetallized acid dyes areexamplified by C.l. 11640, C.l. 11650, C.l. 11836, C.l. 11837, C.l.12695, C.l. 12696, C.l. 12714, C.l. 15681, C.l. 15707, C.l. 15708, C.l.15900, C.l. 13890, C.l. 17941, C.l. 18762, C.l. 18690, C.l. 20018, C.l.12195, C.l. 15675 and C.l. 12197.

Generally, this first dyeing with 1:2 typepremetab lized acid dye isconducted at a liquor ratio of 1:8 to

1:50 for about 1-3hours at a pH of from 5 to 9.

The thus dyed textile material is then combined with undyed textilematerial of the same or similar acrylic polymer containing acid groupsbut no basic groups, by means of, for example, staple-mixing, blending,mixspinning, mix-twisting, mix-weaving, mix-knitting, etc.

Thereafter the entire textile materialissubjected to a second orcross-dyeing with a cationic optical brightener or a cationic ordisperse dye of a color different from that of the 1:2 typepre-metallized acid dye. The second dyeing may be conducted in aconventional manner. Thus, for example, the second dyeing is con ductedin a bath containing 0.1-3.0 percent (based on the weight of the textilematerial) of the dye at pH 3.5-7.0 with a liquor ratio of 1:30 to 1:100.

Examples of cationic dyes useful in the second dyeing are C.l. 42025,C.l. 51005, C.l. 51004, C.l. 42140, C.l. 48055, C.l. 48065, C.l. 48035,C.l. 48040, C.l. 48020, C.l. 48013, C.l. 48015 and C.l. 42040.

The textile material resulting from the second dyeing shows no signs ofbleeding from the first-dyed fiber, that is, no staining of thesecond-dyed fiber. Thus, the resulting material shows an attractive twocolor effect.

The acrylic synthetic fiber containing acid groups but no basic groupswhich is employed according to this invention is an acrylic fiber ofacrylonitrile polymer or an acrylonitrile copolymer (containing atleast80 percent v by weight of acrylonitrile units) free from copolymericEXAMPLE 1 To 97.7 parts of a dyeing bathare added 0.4 part of 1:2 typepre-metallized acid dye, C.l. 15675 and 2.0 parts of sodium sulfate, andparts of acrylic fiber A the dyed fiber is taken out. After soaping, thedyed fiber is washed three times, each with 50 times as much waterrelative to the fiber. The fiber is oiled and then dried.

Then 20 parts of the above dyed fiber are mix-spun with 80 parts ofundyed acrylic fiber A to make a melange" yarn of white and reddishpurple. Two parts of this yarn are dipped in 98 parts of a dye bathcomposed of 0.03 percent cationic dye C.l. 48035, 0.06 percent aceticacid, 0.1percent sodium sulfate, 0.04 percent cationic retarder and99.79 percent water, and is dyed assuc h at temperatures increasing bydegrees from 60 C to about 100 C over a period of 60 minutes, followedby further dyeing at about 100 C for an additional 30 minutes.

The resulting variegated dyed yarn showsno signs of bleeding from thepreviously dyed fiber, that is, no staining of the second-dyed fiber,and the latter fiber thus assumes a bright orange shade. The result isan attractive melange" yarn of orange and reddish purple.

' one of which has been dyed with a first dyeing bath of (a copolymer ofpercent acrylonitrile and 10 per- 6 cationic dye, C.l. 48020, and thenafter blending with the other fiber dyed to a different shade, showsextensive signs of staining of the second-dyed fiber owing to thebleeding-out of dye from the first-dyed fiber, with the total yarnassuming a brownish-color. Thus, the expected effect of variegateddyeing is not observed with this yarn.

EXAMPLE 2 Acrylic fiber B (a copolymer of 91 percent acrylonitrile, 8.8percent methyl acrylate and 0.2 percent allyl sulfonic acid, containing48 millimols of acid groups per kg. of fiber) is dyed by a packagedyeing machine under the following conditions: 5 percent o.w.f. of 1:2type pre-metallized acid dye of the formula 20 percent o.w.f. of sodiumchloride, liquor ratio 1/20, dyeing temperature C, 2 hours. The dyedfiber is taken out from the package dyer and is soaped with 0.5 g/l of anonionic surface active agent (polyoxyethylene lauryl ether) at 60 C for20 minutes, at the end of which time the fiber is washed three times,each time 7 I 8 with 50 times as much water relative to the fiber. TheThe resulting cross-dyed fabric has an attractively fiber is oiled andthen dried. black-dotted pattern, showing no signs of bleeding of Then20 parts of the dyed fiber are mix-spun with 20 the. first dye, that is,no staining of the second-dyed parts of undyed acrylic fiber B toprepare a melange yarn.

yarn, which is dyed under the following conditions: 0.1 On the otherhand, when a first yarn dyed with the percent o.w.f. of cationic dye,CI. 42025, i percent Cationic black dye as in Exampl 2 is mploy theo.w.f. of acetic acid, percent o.w.f. of sodium sulbleeding of dye fromthe first-dyed yarn results in exfate, 3 percent o.w.f. of cationicretarder, liquor ratio tensive staining of the second-dyed yarn. Theentire 1/50, with dyeing bath temperature increasing gradufabric assumesa grayish shade, and the desired effect ally from 60 C to about 100 Cover a period of 1 hour, 10 of Cross dyeing is completely absent.

followed byfurther dyeingat about 100 C for an additional 30 minutes.The resulting yarn shows no sign of bleeding from the first-dyed fiber,with the cross dyed fiber assuming a brilliant pale bluish shade. Thus,a EXAMPLE 4 very satisfactory cross-dyed yarn is obtained.

re 7 1 t On the other hand, a first fiber similar to the first one usedabove is dyed by a package dyeing machine under the followingconditions: 5 percent o.w.f. cationic black dye of the formula Acrylicfiber B is dyed by means of a package dyer underthe followingconditions: 8 percent o.w.f. I12 type pre-metallized acid dye used inExample 2, 20 percent o.w.f. potassium sulfate, liquor ratio l/20,dyeing processed in the same manner as in Example 2 to preparea coloredyarn. 1 part of the dyed yarn is mix-- twisted with 5 parts of yarncomposed of undyed cl acrylic fiber B, and for the purpose of enhancingthe whiteness of the undyed yarn, the mixed yarn is dyed under thefollowing conditions: 0.8 percent o.w.f. cationic optional brightener ofthe formula N\ G bath temper ture 120 C, 2 hours. The dyed fiber is IN=N OH 1 percent o.w.f. sodium acetate, liquor ratio 1 /20, with 10percent o.w.f. sodium sulfate, 1 percent o.w.f. acetic the dyeing bathtemperature increasing gradually from 40 acid, liquor ratio II 100, withthe dye bath temperature 60 C to about 100 C over a period of 40minutes, folincreasing gradually from 60 C to about 100 C over lowedby'further dyeing at about 100 C for an addia period of 40 minutes,followed by further dyeing at tional 90 minutes, at the end of whichtime the dyed about 100 C for 40 minutes. The cross-dyed portion offiber is processed and blended with the second fiberin the resultingyarn shows no signs of stain, and the yarn the same manner as above. Theyarn so prepared is is highly saleable.

cross-dyed as above. The result is that the second-dyed In place ofdyeing with the 1:2 type pre-metallized fiber is extensively stained dueto the bleeding out of acid dye, the fiber to be first-dyed is treatedunder the the first dyed fiber, giving rise to a yarn of poorsalefollowing conditions: 5 percent o.w.f. cationic black ability. dyeused in Example 2, 10 percent o.w.f. sodium sulfate, 1 percent o.w.f.acetic acid, 1.8 percent o.w.f. cat.-

' ionic retardenliquor ratio'l /20, with the dye bath temperatureincreasing gradually from 60 C to 85 C over a period of 40 minutes,followed by further dyeing at I 3 85 C for an additional 10 minutes, andthen increasing Acrylic filyer B 15 y mm the 112 yp P from 5 c to about100 c over a period of 20 min-' metahzsd acld y and after-treated in thea utes, followed by further dyeing at about 100 c for 30 as Example Thefi f' h P?" y minutes. When the resulting yarn is processed as above,one P of'the y y 1S mlx'twlsted w 2 Parts of no beneficial effect ofcross dyeing can be obtained, y Whlch is composed of undyed acrylicfiber-B, and with the dye bleeding out from the first-dyed yarn and ther511ltm$ i y is machine'knitled- The extensively staining thesecond-dyed yarn, the entire resultmgknitted fabric is dyed under thefollowing conproduct assuming a if grayish shade ditions: 0.5 percento.w.f. cationic dye, CI. 48055, 3 percent o.w.f. acetic acid, 1 percento.w.f. sodium acctute, 2.9 percent o.w.f. cationic retarder, liquorratio N20, with the dye bath temperature increasing gradu- EXAMPLE 5ally from 60 C to about C over a period of 40 To 100 parts of a dyeingbath was added 0.3 part of minutes, followed by further dyeing at about100C for the 1:2 type premetallized acid dye used in Example 2,

an additional 45miuutesand ryl b r Bw dysdsnst t thssqmiitiqns st forthin Table 1 for 2 hours. Soaping of the dyed fiber was carried out with lgram/liter of nonionic surface active agent, liquor ratio 1 /20,temperature 60 C, time 30 minutes. The fiber was washed three times,each time with 50 times as much water as the fiber. Finally, the fiberisoiled and dried. The results of the above dyeing are summarized inTable l.

C over 40 minutes, and the dyeing was further continued at about 100 Cfor another 90 minutes. The dyed fiber wasthen blended with undyedacrylic fiber B in the same manner as above. The resulting sliver wasfound to be extensively stained by the dye bleeding out from the.first-dyed fiber, assuming an undesirable apl P9--.

calcium chloride The shade of the dyed fiber is expressed in Y (percent)which denotes the shade of a sample measured for tristimulus values onthe basis of the blue-black standard plate (X: 2.90 percent, Y: 2.90percent, Z: 5.55 percent) by means of a color differential meter (JapanColor Machines, Ltd., Model CM The sample is substantially perfect blackwhen its Y value is less than 1.10 percent.

It can be seen from Table 1 that under dyeing condition 1, i.e., at thedye bath temperature of 100 C and in the absence of the salt, the fiberis dyed only a pale shade, but that when the dye bath temperature is 120C as under condition 11, the diffusion of the dye is promoted even inthe absence of the salt, with the result that although the final shadeis dark, rich gray, it is impossible to obtain a desired black product.It was possible to obtain nearly black fibers when the alkali metal saltadded is sodium sulfate as in the case of conditions III and 1V. Undercondition V, i.e., when calcium chloride, which is a water-solubledivalent metal salt, is added, a substantially perfectly black fiber canbe obtained.

Then 10 parts of the fiber dyed under dyeing condition V where mix-spunwith 90 parts of undyed acrylic fiber B, and the resulting mottledsliver is dyed under the following conditions 0.2 percent o.w.f.cationic dye, CI. 42025, 1 percent o.w.f. acetic acid, 10 percent o.w.f.sodium sulfate, 3 percent o.w.f. cationic retarder, liquor ratio l/50,the bath temperature gradually increasing from 60 C to about 100 C over60 minutes, and the dyeing continued at about 100 C for an additionalminutes. The dyed fiber was washed with water, followed by drying. Thefinal variegated dyed fiber was completely free from stain and thesecond-dyed portion of the same fiber assumed a bright, pale blue shade.Thus,there was obtained an extremely superior variegated dyed fiber.

On the other hand, the first-dyed fiber was prepared by dyeing acrylicfiber B by meansof a package dyer; under the following conditions: 5percent o.w.f. cationic black dye used in Example 2, 1 percent o.w.f.sodium acetate, liquor ratio 1/20, with the dye bath temperaturegradually increased from 60C to about 1 0 0 EXAMPLE 6 Table 2 Sodiumchloride Amount of inorganic salt (m.mole) Control (none) 92 .8Inorganic salt Sodium sulfate Barium chloride Zinc chloride Magnesiumchloride 0 0 0. 0 0 Calcium chloride 0 The shade of the dyed fiberisrepresented by the K/S value, which is obtained by measuring thereflectivity R of the dyed fiber at a wavelength of 580 millimicro ns,and then calculating K/S by means of the following equation:

When the dyeing is carried out in the absence of salt, the fiber ismerely stained, but the addition of salt promotes dyeing. In addition,while the fiber is dyed darker as the amount of salt is increased,irrespective of the type of salt, the employment of alkali salts such assodium chloride, sodium sulfate, etc. gives K/S values ranging from 1.6to 3.7 which are equivalent to pale to medium shades. When water-solubledivalent metal salts are added, the K/S values of the resulting fibersare at least equal to 4.0 or higher, that is, the fibers are ysidarkcr ta medium S ad .utes and the dyeing continued for an additional 60minutes, at the end of which time the dyed articles were washed anddried. As for the final variegated dyed knits, the articles dyed inaccordance with the present invention yielded superior dyed productshaving a brillantly variegated pattern of blue and orange-yellow.

EXAMPLE 7 Acrylic fiber A was dyed for 120 minutes using a dye bathcontaining a 1:2 type pre-metallized acid dyeand a watersolubleinorganic salt as shown in Table 3, at a liquor ratio of H and atemperature of 120 C. The fiber dyed this way, as well as undyed acrylicfiber A, was spun into slivers which are then mix-plied into a singlesliver in which the two components were arranged in asymmetricalpattern, and this single sliver was further mix-plied to prepare a fiberwith a mottled pattern. This fiber was then dyed under the followingconditions: 0.5 percent o.w.f. cationic dye, CI. 48055, 1 percent o.w.f.acetic acid, liquor ratio 1] 100, with the bath temperature increasedgradually from 60 C to 90 C over about 30 minutes, followed by boilingfor another 60 minutes.

The degrees of staining of variegated dyed fibers prepared in thedescribed manner are summarized in T b e 3- were precisely weighed at g.

were put into the same beaker fitted with a reflux conmore staining thanwould be represented by the value 3, but less staining than would berepresented by the value 2.

Whatwe claim is: I

1. In a process for preparing multi-colored acrylic fiber textilematerial which comprises dyeing a first textile material of an acrylicfiber containing an augmented number of acid groups but no basic groups,combining the dyed textile material with a second textile material of anundyed acrylic fiber containing an augmented number of acid groups butno basic groups by blending the dyed and undyed textile materials, andthereafter dyeing the resultant material with a cationic or dispersedye, the improvement according to which the dyeing of the first textilematerial is conducted at a temperature of at least 100 C in a first dyebath containing a dilute solution of a neutral dyeing 1:2 typepre-metallized acid dye and 0.5-5.0 percent by weight, based 9n theai slt t thsdys hath. of at ast on sal Table 3 First-dyeing conditionsStaining Staining of of first second-dyed Dyestufi Salt added dyed fiberfiber by e by second bleeding-out C.l. No. Concen- Concendye of firstdye tration Type tration (l6 owl) owl) 17941 3 Nn,SO, 20 3 4 5 do. 3BaCl, 2O 4 4 5 15675 5 Na,SO, 20 2 3 3 do. 5 8:101, 20 4 3 4 15707 5Na,S0, 20 2 3 4 5 do. 5 BaCl, 20 4 4 5 dyed acrylic fiber and the sameundyed acrylic fiber 6O selected from the group consisting of calciumchloride, barium chloride, zinc chloride, magnesium chloride, cadmiumchloride, zinc sulfate, magnesium sulfate, zin nitratesa mism nll'fltill .@ill m..h.l9 @3 2. The improvement as claimed in claim 1,wherein the first textile material is dyed at l00l 30 C.

1. IN A PROCESS FOR PREPARING MULTI-COLORED ACRYLIC FIBER TEXTILEMATERIAL WHICH COMPRISES DYEING A FIRST TEXTILE MATERIAL OF AN ACRYLICFIBER CONTAINING AN AUGMENTED NUMBER OF ACID GROUPS BUT NO BASIC GROUPS,COMBINING THE DYED TEXTILE MATERIAL WITH A SECOND TEXTILE MATERIAL OF ANUNDYED ACRYLIC FIBER CONTAINING AN AUGMENTED NUMBER OF ACID GROUPS BUTNO BASIC GROUPS BY BLENDING THE DYE AND UNDYED TEXTILE MATERIALS, ANDTHEREAFTER DYEING THE RESULTANT MATERIAL WITH A CATIONIC OR DISPERSEDYE, THE IMPROVEMENT ACCORDING TO WHICH THE DYEING OF THE FIRST TEXTILEMATERIAL IS CONDUCTED AT A TEMPERATURE OF AT LEAST 100*C IN A FIRST DYEBATH CONTAINING A DILUTE SOLUTION OF A NEUTRAL DYEING 1:2 TYPEPRE-METALLIZED ACID DYE AND 0.5-5.0 PERCENT BY WEIGHT BASED ON THEWEIGHT OF THE DHY BATH, OF AT LEAST ONE SALT SELECTED FROM THE GROUPCONSISTING OF CALCIUM CHLORIDE, BARIUM CHLORIDE, ZINC CHLORIDE,MAGNESIUM CHLORIDEE CADMIUM CHLORIDE, ZINC SULFATE, MAGNESIUM SULFATE,ZINC NI-
 2. The improvement as claimed in claim 1, wherein the firsttextile material is dyed at 100*-130* C.